Stocking manufacture



United States Patent STOCKING MANUFACTURE Application November 28, 1955Serial No. 549,533

Claims priority, application Netherlands December 2, 1954 2 Claims. (Cl.28-74).

No Drawing.

This invention relates to a process for the manufacture of stockingsfrom high molecular weight synthetic linear polyamide threads delusteredwith titanium dioxide, which stockings are destined to be so dyed in oneoperation that the heel of the stockings has a darker color than the legof the stockings. This invention also relates to stockings manufacturedaccording to said process.

The manufacture of such stockings has been executed heretofore invarious ways. According to one method, the leg and the heel of thestocking are knitted from different types of polyamides which dyedifferently in the same bath. It is obvious that in employing thatmethod, the polyamide which dyes to the darkest color will beincorporated in the heel. In the dyeing of such a stocking the heelportion of the stocking acquires a darker color. With the methoddescribed, however, the effect desired in the stocking industry, viz.that the heel and the leg of the stocking shall be distinguishable indarkness but not in shade, is not obtained. Due to the difference instarting material of the threads a difference in shade is inevitablyobtained.

According to another known method the leg portion and the heel portionof the stocking are made from the same type of polyamide but the threadstobe incorporated in the heel portion are pretreated so as to increasethe dyeing affinity of the polyamides. This method has the disadvantagethat it requires an additional treatment of the threads before theknitting operation as well as that the additional treatment takes placewhile the threads are wound on a spool and therefore while they are lessaccessible for a uniform liquid treatment.

It is also known to dye the polyamide threads destined for the heelbefore the knitting operation. This method has the disadvantage that onthe warm molding of the knitting stocking, wrinkles will form on theboundary of the leg and the heel due to the fact that the threads of theleg have not been exposed to an elevated temperature as have the threadsof the heel, viz. in the previous dyeing.

The object of the present invention is to make it possible to dye in oneoperation stockings made from threads of high molecular weight syntheticlinear polyamides (hereinafter sometimes called simply polyamides forconvenience and brevity) so that the heel or other predetermined portionor portions of the stocking will be given a darker color than the leg orother predetermined portion or portions, respectively, of the stocking.

The manner in which these and other objects and features of theinvention are attained will appear more fully from the followingdescription thereof, in which reference is made to typical and preferredprocedures in order to indicate more fully the nature of the invention,but without intending to limit the invention thereby.

The process according to the present invention is characterized in thatof the foot portion of the stockings at least the heel is formed frompolyamide threads containing carbon black as well as titanium dioxide,the

2,913,801 Patented Nov. 24, 1959 latter being employed in theconventional delustering amounts.

With a stocking thus manufactured the heel portion is not dyed moredeeply than the leg portion on dyeing in one and the same bath, but theheel portion acquires a darker color due to the presence of the carbonblack. It is surprising, however, that no difference in shade occursthereby which, as indicated above, is considered to be of greatadvantage in this branch of the textile industry.

Preferably a portion of 0.02-0.10% by weight of carbon black is employedin the polyamide threads con- I taining carbon black and titaniumdioxide, and excellent results are obtained with a proportion of 0.05%by weight of carbon black. The titanium dioxide is employed in theconventional delustering amounts'such as from 0.22% by weight, excellentresults being obtained with 0.3% TiO for multifilament yarns and 0.5%for monofil. Here and elsewhere, the ratios indicated are based on theweight of the polyamide threads.

The titanium dioxide and the carbon black are incorporated in thethreads in any desired manner, the details of which form no part of thepresent invention.

' Preferably, however, this is done by rolling the polyamide grainsdestined for meltspinning according to the grid process first with thetitanium dioxide and then with the carbon black.

Although reference has been made primarily to a darker colored heelportion, it should be understood that the process according to thepresent invention may also be applied in the manufacture of stockings ofwhich besides the heel portion also the toes (or indeed any otherpredetermined portions) are to be made much darker than the leg portion.

The term carbon black includes also carbon pigments related theretowhich pigments may have been subjected to an aftertreatment fordeepening the black color thereof.

While a specific example of a preferred method embodying the presentinvention has been set forth above, it will be understood that manychanges and modifications may be made in the methods of procedurewithout departing from the spirit of the invention. It will therefore beunderstood that the particular proportions and methods of operation setforth above are intended to be illustrative only, and are not intendedto limit the scope of the invention.

What is claimed is:

1. A process for the manufacture of stockings from polyamide threadswhich comprises incorporating into polyamide about 0.22% by weight oftitanium dioxide and about 0.02-0.10% by weight of carbon black,meltspinning the polyamide into threads, knitting the threads into aportion of a stocking having the other portion knitted from polyamidethreads of like composition but containing no carbon black, and dyeingthe stocking in one operation.

2. A process for the manufacture of stockings from polyamide threadswhich comprises rolling polyamide in granular form in the presence ofabout 0.022% by weight of titanium dioxide and about 0.02-0.10% byweight of carbon black, meltspinning the polyamide according to the gridprocess, knitting the threads into a portion of a stocking having theother portion knitted from polyamide threads of like composition butcontaining no carbon black, and dyeing the stocking in one operation.

Garothers Sept. 20, 1938 Herzog July 9, 1957

1. A PROCESS FOR THE MANUFACTURE OF STOCKINGS FROM POLYAMIDE THREADSWHICH COMPRISES INCORPORATING INTO POLYAMIDE ABOUT 0.2-2% BY WEIGHT OFTITANIUM DIOXIDE AND ABOUT 0.02-0.10% BY WEIGHT OF CARBON BLACK,MELTSPINNING THE POLYAMIDE INTO THREADS, KNITTING THE THREADS INTO APORTION OF A STOCKING HAVING THE OTHER PORTION KNITTED FROM POLYAMIDETHREADS OF LIKE COMPOSITION BUT CONTAINING NO CARBON BLACK, AND DYEINGTHE STOCKING IN ONE OPERATION.